Headblock and knee assemblies for sawmill carriages



Sept. 2, 1969 T. F. MEIS 3,464,467

IIEADBLOCK AND KNEE ASSEMBLTES FOR SAWMILL CARRIAGES Filed May 16, 19672 Sheets-Sheet 1 INVENTOR THOMAS P. MEIS AT TORNEYS T. F. MEIS Sept. 2,1969 1 HEADBLOCK AND KNEE ASSEMBLIES FOR SAWMILL CARRIAGES 2Sheets-Sheet 2 Filed May 16, 1967 INVENTOR THOMAS F. MEIS ATTORNEYS3,464,467 HEADBLOCK AND KNEE ASSEMBLIES FOR SAWMILL CARRIAGES Thomas F.Meis, P.0. Box 27, Mondovi, Wis. 54755 Filed May 16, 1967, Ser. No.638,798

Int. Cl. B27]: 29/08 US. Cl. 143-120 3 Claims ABSTRACT OF THE DISCLOSURETo provide a smoothly operable headblock and movable knee assembly for asawmill carriage the invention includes a channel-shaped headblockwithin which there is movably carried a wheeled base member supportingan upright long-engaging knee, the wheeled design of said knee unitreducing friction and wear as said unit is shifted within said headblockto adjust the position of a log for succeeding longitudinal cuts, andwhich improved assembly includes means for preventing sawdust and woodchips from accumulating in said headblock and impeding the movement ofsaid adjustable knee unit.

BACKGROUND OF THE INVENTION Field of the invention The present inventionpertains to lumber sawmills of the type used for sawing logs into boardsor planks, and more specifically to the so-called headblock and kneeassembly which is an integral part of a sawmill carriage.

Description of the prior art In conventional sawmill carriages aplurality of upright knee members are slidably mounted in and projectupwardly from and in right angular relationship to horizontal headblocksupon which the log to be sawed is rested, the function of said kneemembers being to abut against and maintain said log in proper positionas it moves into engagement with the saw. After a board or plank hasbeen sawed from the log the carriage is returned to its startingposition and said knees shifted a a predetermined distance tore-position the log for the next cut, depending upon the desiredthickness of the board. Unfortunately, with such slidable knee unitsthere is unavoidable friction and power loss during their adjustment,and there is uneven wear on said headblock and knee members whichfrequently causes said knee to become misaligned from the true vertical,resulting in imperfect or so-ealled out of square boards.

As far as applicant is aware, no one has heretofore employed a wheeledknee unit within a sawmill carriage headblock, in contrast toconventional sliding type knee units, nor has anyone utilized applicantsmeans for purging sawdust and wood particles from the assembly duringoperation, as will be hereinafter described.

SUMMARY OF THE INVENTION The present invention provides a novel andimproved headblock and knee assembly for a sawmill carriage wherein thelog-positioning knees are mounted on wheels or rollers to permit theirfree rolling movement within the headblocks, in contrast to conventionalsliding knee members. The reduced friction lessens the powerrequirements and also substantially lessens wear on said relativelymovable parts, thus ensuring that said headblock and knee members aremaintained in right angular relationship to provide true and accuratesawed boards.

A further feature of the invention is that said knee unit rollers areprovided with annular V-shaped grooves therein to aceomodate sawdust orwood particles accumulating in said headblocks, and are self-cleaning toStates atent prevent such particles from impeding the travel of saidknee unit. In addition, scraper bars are also provided on said movableknee unit to continuously purge larger wood chips and the like tofurther ensure the smooth travel of said unit.

Still further important objects of the present invention are=:to providea novel and improved headblock and knee assembly for sawmill carriagewhich is relatively simple in design and construction, which is reliablein operation, and which is otherwise particularly well adapted for itsintended purposes.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, wherein the samereference numerals designate the same or similar parts in all of theviews:

FIG. 1 is a simplified perspective view of a sawmill carriage, the novelheadblock and knee assembly comprising the invention being indicated infull lines and the associated carriage structure being shown in dot anddash lines;

FIG. 2 is a perspective view of the wheeled knee unit featured in theinvention;

FIG. 3 is an enlarged side elevational view of the headblock and kneeassembly, with a part of said headblock broken away to show the kneeunit base therein; and

FIG. 4 is an end view, looking into the forward end of saidchannel-shaped headblock, showing the wheeled knee unit mounted therein.

DESCRIPTION OF THE PREFERRED EMBODIMENT As is shown in FIG. 1, thecomplete sawmill assembly of which the present invention is a partincludes a carriage 10 having wheels 11 designed to ride on paralleltracks 12, and mounted on and extending transversely across saidcarriage are a plurality of channel-shaped headblocks 13 upon which thelog 14 to be sawed is positioned, said log being rested against two ormore upright knee members 17. The number of headblocks and kneesutilized can be varied, depending upon the size and style of thesawmill, and the invention is not to be limited in this respect.Suitable hydraulic drive means or other means for driving the carriageare provided for moving said log into engagement with a high speedrotary saw 16, and as said blade traverses the length of said log itfunctions to cut a board or plank therefrom. The entire assembly ispreferably of welded steel construction, and can be either portable orpermanent, as desired.

After the initial cut the carriage 10 and log are returned to theillustrated position, and the knee members 17 are moved forwardly apredetermined distance, depending upon the desired thickness of the nextboard to be cut. Interconnected rack and pinion members 18, 19 or othersuitable adjustment means are provided for shifting said upright kneemembers 17, said adjustment being controlled by an operator, and inconventional headblock and knee assemblies the base portions of saidknee members are merely slidably housed within the channel-shapedheadblocks. Unfortunately, and as hereinabove mentioned, with suchconventional headblock and knee units there is unavoidable frictionbetween said relatively movable parts which not only increases the powerrequirement, but which also causes considerable wear on said parts.Moreover, it has been found that the wear on said relatively movablemembers develops unevenly, with the predominant wear occurring adjacentthe forward end of the knee unit. The result is that the uprightportions 21 of said knee units are biased from their right angular rela-It is to eliminate this shortcoming of conventional sawmill carriageheadblock assemblies that the novel unit comprising the presentinvention has been designed.

With reference now to FIGS. 2-4 of the drawings, it will be seen thatthe knee unit featured in the present invention, which is designatedgenerally by the numeral 17, includes a vertical leg member 21 which isrigidly Welded or otherwise secured to a base 24, there being a brace orreinforcing element 22, and a bracket 20 (FIG. 2) may be provided forthe attachment of the adjustment rack 18. The forward vertical edge ofsaid upright leg member is preferably flanged as at 23 to provide a flatsurface against which a log can be positioned.

The base portion 24 of said knee unit is an elongated and relativelynarrow upright member, as shown, and is provided with forward andrearward axles 26, 27, upon which there are mounted wheels or rollers 28and 29, respectively, a set of said rollers being mounted on each sideof said base. As best appears in FIG. 4, each of said rollers includes apair of spaced, beveled annular grooves 31, there being fiat,surface-engaging portions therebetween, which grooves have an importantfunction in the operation of the present invention, as will behereinafter seen. Supported by and depending from said base member 24immediately in front of the forward wheels or rollers 28 is a scraperbar 33. Said bar extends across the width of said base unit and projectsdownwardly to a point spaced just above the bottom surface of theheadblock, and a similar scraper bar 34 is mounted immediatelyrearwardly of the rollers 29 at the opposite end of said base member.

As is shown in FIGS. 3 and 4, the wheeled base portion 24 of the kneeunit in the present invention is mounted within the channel-shapedheadblock 13, said headblock being channel-shaped and generallyrectangular in cross section (FIG. 4), and being precision machined forclose internal tolerances, as there doesnt have to be any allowance madefor sliding and canting of the knee unit therein, as in conventionalheadblock assemblies. Said headblock 13 is mounted on a suitable base 36and includes a longitudinal slotted opening 37 in its bottom wall and alongitudinal top opening 38 through which the upper portion of saidmember 24 projects. As will be seen in FIG. 4, the rollers 28 (as wellas the rearward rollers 29') are designed to fit closely but rotatablywithin said channel-shaped headblock, and the scraper bars 33, 34 spansubstantially the entire internal dimension of said headblock.

In the operation of the novel headblock and knee assembly comprising thepresent invention, after a log 14 has been positioned on the horizontalheadblocks 13, which may be accomplished by means of an automaticconveyor system or any other suitable means, the movable knee units areadjusted and set so that the upright knee portions 21 bear against saidlog and locate the same relative to the saw 16 so that a board ofdesired thickness will be cut from said log as the carriage traversessaid saw. As hereinabove mentioned, operatorcontrolledhydraulically-powered rack and pinion units 18, 19 can be used for thispurpose, although other adjustment mechanisms can also be employed andthe invention is by no means to be limited in this respect.

After each succeeding longitudinal cut of the log said knee units 21must be advanced a short distance, of course, to reposition the log forthe next pass through the saw. The result is that when a quantity oflogs is being sawed, as is frequently the practice, conventional slidingtype knee units are subject to considerable friction and wear, with theundesirable effects hereinabove enumerated. With the roller actionprovided by the present invention, however, such friction and wear issubstantially eliminated. Moreover, because of their continuous rollingmovement during adjustment of the knee members, any wear that does occuron said rollers is distributed evenly, thus prevenaing misalignment ofthe knee upright portions 21 and ensuring boards of uniform squarenessand quality.

As will be readily appreciated, during the sawing operation it isunavoidable that sawdust and wood particles constantly find their wayinto the channel-shaped headblocks 13. Heretofore the accumulation ofsuch foreign material within the headblocks tended to impede the slidingmovement of the knee unit therein, and was a source of considerabletrouble and annoyance. With the novel knee knit comprising the presentinvention, however, as the base portion 24 thereof moves forwardlywithin the headblock the scraper bar 33 at the forward end of said basefunctions to sweep the larger wood particles and chips out of saidheadblock, and on the return travel of said knee unit the scraper bar 34at the opposite end of the base performs the same function, thuscontinuously purging the unit of said wood chips.

With respect to sawdust and finer wood particles accumulating in saidheadblock, the novel tapered annular grooves 31 in the rollers 28, 29are designed to force said particles into narrow windows permitting saidgrooved rollers to pass easily thereover. As said roller grooves becomefilled and the rollers pass over more particles the later force thepreviously-retained particles out of said grooves, thus providing acontinuous selfcleaning action which promotes the smooth operation ofthe knee unit within the headblock.

From the foregoing detailed description it will be seen that the presentinvention provides a novel headblock and movable knee assembly forlumber sawmill carriages having several important advantages over priorstructures intended for the same purpose. In the present invention theadjustable log-positioning knees are mounted on Wheels or rollers whichpermit their free rolling movement within the headblock, in contrast tothe sliding knee units employed in conventional sawmill carriages. Theresult is reduced friction and power requirements and also substantiallyless wear on said relatively movable parts, thus ensuring that saidheadblock and knee members are maintained in right-angular relationshipto prevent sawed boards that are out of square.

A further feature of the invention is that said knee unit rollers areprovided with annular V-shaped grooves to accommodate sawdust and woodparticles accumulating in the headblocks, and cooperating scraper barsare provided at the ends of said movable knee units to continuouslypurge the larger wood particles and chips from said headblocks.

It is to be understood that while a preferred embodiment of the presentinvention has been illustrated and described herein, numerous variationsor modifications thereof are possible. What is intended to be coveredherein is not only the illustrated form of said invention but also anyand all variations or modified forms thereof as may come within thespirit of said invention, and within the scope of the following claims.

I claim:

1. In a sawmill carriage including a horizontal channelshaped headblockhaving a fiat bottom wall portion and a fiat top wall portion with aslotted opening therethrough, said headblock being adapted to have a logrested transversely thereacross, including a knee unit with a basemovably carried in said headblock and a leg projecting upwardly throughsaid top wall opening in right angular relationship to said headblockengageable against a log positioned on said headblock, and includingpower means for moving said knee unit longitudinally of said headblockto shift the position of a log engaged by said upright leg, theimprovements comprising: a knee unit base mounted within saidchannel-shaped headblock having a forward end and a rearward end;rollers mounted on opposite sides of said knee unit base member, saidrollers riding on the flat bottom portion of said channel-shapedheadblock; peripheral grooves formed in said rollers adapted to receiveand temporarily retain wood particles accumulated on the bottom of saidheadblock interior to promote the smooth, unimpeded rolling movement ofsaid knee unit base within said headblock; an elongated slotted openingin the flat bottom portion of said channel-shaped headblock throughwhich wood chips can be evacuated from the headblock interior;laterally-extending scraper bar means on said knee unit basesubstantially spanning the side walls of said headblock and adapted tosweep wood particles from the interior of said headblock during travelof said knee unit to further promote the unimpeded movement thereof.

2. The sawmill headblock and movable knee assembly recited in claim 1and wherein said roller peripheral grooves are beveled to provideself-cleaning action as Wood chips accumulate therein.

3. The sawmill headblock and movable knee assembly recited in claim 1wherein said rollers are closely rollably fitted within saidchannel-shaped headblock to maintain said knee unit upright leg inright-angular relationship to said headblock.

References Cited UNITED STATES PATENTS 730,773 6/1903 Kincaid 308-61,768,029 6/1930 Bratlie 143124 1,923,853 8/1933 Van Duyn 3086 X2,861,606 11/1958 Fish 143120 FOREIGN PATENTS 1,118,468 6/ 1958 France.

ANDREW R. JUHASZ, Primary Examiner GIL WEIDENFELD, Assistant ExaminerUS. Cl. X.R. 143124; 308-6

